1. The Field of the Invention
The invention relates to a coupling device for connecting a light guide.
2. Background and Relevant Art
Optical coupling devices, in particular plug-in connections or screw connections, are known for optically connecting a light guide, for example an optical fiber, to other optical components or further light guides. In order to ensure a reliable transmission of the light, the light guide and the further optical component or the two light guides must be joined to one another or aligned with one another with particular accuracy with reference to the light propagation direction or the optical axes in the coupling device so that the light or the light signal is transmitted as completely as possible. Moreover, especially at their particularly sensitive ends, the sensitive optical fibers must be protected against mechanical damage.
One possible application of light guides is for transmitting light, in particular laser light, for processing materials or for the medical treatment of humans or animals, in particular in opthalmology, for example in the explantation of the natural eye lens during cataract operations in the course of the phacoemulsification during which shock waves produced by means of laser light emulsify the lens and are exhausted (photolysis), or in operations on the cornea, for example for treating myopia.
Another application is the transmission of information relating to light signals through light guides in metrology, communications technology and data systems technology.
EP 0 898 186 A1 discloses a plug-in connection for centered connection of a light guiding fiber, or for centered coupling of two light guiding fibers, that has a plug and a socket with a cutout in which the plug engages. The light guiding fiber is led through the socket and ends with a fiber end in a bore in the plug that expands in a funnel-shape fashion in the direction of the socket. In order to protect it against mechanical damage, the optical fiber is rigidly held in a tube that surrounds the fiber inside the bore of the plug up to the fiber end. The socket and the plug with the funnel-shaped section of this known plug-in connection are produced from plastic, preferably as injection-molded parts.
In a further plug-in connection, which is known in practice and constructed in a fashion similar to the embodiment in accordance with EP 0 898 186 A1, the optical fiber is not surrounded by a tube, but its end projects freely into the funnel-shaped section of the plug. The plug with the funnel-shaped inner surface is manufactured from metal, specifically high grade steel, by turning, and is mostly also redressed. When the plug and socket are plugged together, the funnel serves as a guiding and centering aid for the light guide.